Since the domestic and international industrial waste gas, vehicle exhaust gas emission standards are more stringent, the requirement for the industrial waste gas and vehicle exhaust gas purification catalyst is getting higher and higher. As a source of mobile pollution, vehicles continuously change the exhaust gas components and properties in the course of running so that the ordinary catalyst is difficult to effectively purify the vehicle exhaust gas. Thus a vehicle exhaust gas purification catalyst and a motorcycle exhaust gas purification catalyst containing precious metals, such as platinum, palladium, rhodium, are developed. These catalysts use a key active coating material, that is, cerium-zirconium composite oxide material. The cerium oxide in the cerium-zirconium composite oxide has valence variability, and Ce4+ and Ce3+ change in the oxidizing or reducing atmosphere, so that the cerium-zirconium composite oxide has the function of storing oxygen, which can effectively expand the catalyst air-fuel ratio window and substantially increase the catalytic purification performance of vehicle exhaust gas catalyst. Cerium-zirconium composite oxide is used in automotive exhaust gas catalyst, which also needs to withstand the degradation temperature of higher exhaust gas so as to maintain the stability of the material structure and performance. Therefore, cerium-zirconium composite oxide with a high specific surface and an excellent performance is currently widely used in the vehicle exhaust gas purification catalyst, which has become an irreplaceable key material for the vehicle exhaust gas purification catalyst.
For catalysts prepared with cerium-zirconium composite oxide, the high specific surface is usually necessary. However, under the action of high temperature of automobile exhaust gas, the specific surface of cerium-zirconium composite oxide will decrease and the performance will deteriorate. In order to meet the more stringent vehicle exhaust gas emission standards, the development of cerium oxide zirconium composite oxide with a high specific surface, high stability, and high storage has become an inevitable trend. However, the high temperature stability of the cerium-zirconium composite oxide prepared by the prior art is still insufficient, thereby affecting the catalytic performance of the cerium-zirconium composite oxide. Patent CN101096012 (B) mentions cerium oxide and zirconium oxide-based mixed oxide for the purpose of improving the dispersibility of the precious metal platinum. The ratio of cerium oxide of such mixture species is 50 vol % or more, and such cerium-zirconium oxide has a poor anti-aging resistance. The ratio of cerium oxide is 80.6 vol % and the specific surface area is only 14.4 m2/g when being aged at 1000° C. for 3 h. Patent CN101024513B reports a cerium-zirconium composite oxide having rod-like particles, but it does not precisely describe its mechanism for the formation of rod-like particles. The ratio of rod-like particles is not controllable, which greatly limits the stability of the product production and the consistency of the catalytic application effect.